Cyanobacteria Project

The Cyanobacteria project was first started by our iGEM students in 2016. A couple of advanced undergraduates wanted to work on cyanobacteria, which are photosynthetic blue-green algae. Under the guidance of Professors Mishler and Barrick, the project started in 2016, and it has become an active area of research in the Microbe Hackers lab with students working both on characterizing the growth of these bacteria (we use several Oscillatoria species) and genetically engineering the bacteria to serve as biosensors for water pollutants.

Along the way, this work has been supported by the UTEX Culture Collection of Algae and the curator, Dr. Nobles, with many hours of input, feedback, advice, and of course culture samples.

Our active subprojects:

THP + OHC14 Biosensors. Because biosensors for water pollutants can be unreliable, we are using well-characterized biosensors for THP and OHC14 as proof-of-concept. Each plasmid expresses a fluorescent protein in the presence of their corresponding substance. Our overall goal is to put these plasmids into the bacteria that live on cyanobacteria, allowing them to coexist in a single culture. With this system, just one cyanobacteria filament could be used to detect multiple different substances at the same time. Currently we are working on testing the efficacy of the THP and OHC14 biosensors, getting the plasmids into the bacteria that live on cyanobacteria, and putting the engineered bacteria onto the cyanobacteria filaments.

Riboswitches. We are experimenting with biosensors that use riboswitches, regulatory ligand-binding RNA sequences, instead of repressor proteins, to control expression of our fluorescent output. For example, our theophylline riboswitch biosensor expresses green fluorescent protein when the riboswitch binds theophylline. Currently, we are working on improving the degree to which these switches can be turned on or off.